Typewriter

ABSTRACT

The operating characteristics of an inexpensive typewriter intended primarily for juvenile use are improved with respect to the ribbon drive and reversal of ribbon drive direction and with respect to the carriage escapement. A single lever positions two cams so that one reel is driven by key action and draws in ribbon while the other is free-running and feeds out ribbon. Shifting the lever, positions the cams to shift the drive from one reel to the other with reversed direction of rotation and thus changes the direction of ribbon travel. The carriage escapement is contained in a single cartridge and is driven by both key action and space bar action. The cartridge also provides a mount for a ribbon-vibrator.

United States Patent [191 Kuramochi [54] TYPEWRITER [75] Inventor: ShigeakiKuramochi,Tokyo,Japan [73] Assignee: Louis Marx & Co., Inc., New York,

[22] Filed: May 10, 1971 [21] Appl.No.: 141,861

[52] US. Cl. ..l97/85, 197/68, 197/94, 197/159 [51] Int. Cl. ..B4lj 1/32 [58] Field of Search ..197/82, 85, 94, 68, 19, 20, 197/159 [56] References Cited.

UNITED STATES PATENTS 1,140,848 5/1915 Petennann .t .,..l97/85 1,965,677 7/1934 Trego ..197/85 2,724,479 11/1955 Durkee ..l97/68 3,562,493 2/ 1971 Malkowski et a]... ..l97/20 X Hishida 197/82 1 Apr. 3, 1973 p Primary Examiner-Robert E. Puifrey Assistant Examiner-R. T. Rader Attorney-Elam, Moscovitz, Friedman 8: Kaplan 57 ABSTRACT The operating characteristics of an inexpensive typewriter intended primarily for juvenile use are improved with respect to the ribbon drive and reversal of ribbon drive direction and with respect to the carriage escapement. A single lever positions two cams so that one reel is driven by key action and draws in ribbon while the other is free-running and feeds out ribbon. Shifting the lever, positions the cams to shift the drive from one reel to the other with reversed direction of rotation and thus changes the direction of ribbon travel. The carriage escapement is contained in a sin gle cartridge and is driven by both key action and space bar action. The cartridge also provides a mount for a ribbon-vibrator. 4 i

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PATENTEDAPR 3 I973 lll ll ATTORN Y3 PATENTEDAPR 3 I975 SHEET 5 BF 5 INVENTOR Xmas/0M M/Rmwm/ PATENTED APR 3 I975 sum 6 BF 5 TRIPS.

BY ymul ATTORNEY3 TYPEWRITER BACKGROUND OF THE INVENTION Typewriters of various sorts intended for portable and juvenile use where the typewriters are simply and inexpensively fabricated have been marketed for some time. Such prior typewriters have generally made substantial sacrifices in performance for the sake of reduced cost and certain marketed machines have operated rather poorly particularly with respect to key touch or action.

SUMMARY OF THE INVENTION The ribbon transport mechanism is activated by depression and release of a key, thereby rotating a transverse shaft forward and backward. Pins at either end of the shaft, are each disposed to drive one of two ribbon reel assemblies in opposite directions by means of pawl and ratchet wheel arrangements. A pair of linked cams can be placed in either of two positions, in

each of which only one of the ribbon reel assemblies is coupled to a pin on the shaft the other being free to rotate under pull of the ribbon, thus providing for drive of the ribbon in either direction. Economy of cost and space in the drive mechanism are effected by use of molded plastic components molded integrally with biasing fingers where needed.

A second improvement in typewriters of the sort under consideration is the placement of the carriage escapement, the carriage drive, the carriage release and the release for removing the carriage from the typewriter bed in a single compact, molded cartridge. The cartridge further provides a mount for the support of a. ribbon vibrator which raises the ribbon into printin g positionwith the depression of each key.

The small size of the cartridge is achieved by providing integrally molded fingers on all of the components to be biased, with the exception of the carriage drive, and by molding in thevarious needed. pins, bosses, recesses, notches and bearings.

Accordingly, an object of the invention is to provide a typewriter having improved action.

A further object of the invention is to provide an improved ribbon drive assembly capable of reversal.

Still another object of the invention is to reduce the size and weight of the carriage drive, the carriage escapement, the carriage release, the latch for. removal of the carriage from the typewriter and the ribbon vibrator.

Still other objects and advantages of the invention will in part be obvious and will .in part be apparent from the specification.

The invention accordingly comprisesthe features of construction, combination of elements, and arrangement parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of the invention, reference is had to the following description taken in connection with he accompanying drawing, in which:

FIG. 1 is a plan view of the typewriter according to the present invention with the cover removed and part of the casing broken-away;

FIG. 2 is a partial sectional view taken along line 2-- 2 of FIG. 1;

FIG. 3 is a partial sectional view taken along line 3- 3ofFIG. 1',

FIG. 4 is a partial sectional view of the ribbon reel assemblies taken along 4-4 of FIG. 3;

FIG. 5 shows one of the ribbon reel assemblies of FIG. 4 with a support plate displaced from its rest position;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 4',

FIG. 7 is an exploded perspective view of a ribbon reel assembly;

FIG. 8 is a sectional view taken along line 8-8 of.

FIG. 2 with parts broken away for the sake of clarity;

FIG. 9 is a partial sectional view taken along line 9- 9 of FIG. 8; FIG. 10 is a partial sectional view taken along line 10-10 of FIG. 9; I

FIG. 11 is a partial sectional view taken along line FIG. 12 is a partial view similar to FIG. 8' with the carriage moved one tooth; I

FIG. 13 is an exploded perspective view of the slidebar and pawls which activate the escapement;

FIG. 14 is a partial sectional view taken along line. 1414of FIG. 8; and

FIG. 15 is a partial sectional view taken, along line 15-15 of FIG. 14. Y

DESCRIPTION OF THE PREFERRED EMBODIMENTS A typewriter having a construction in accordance with the present invention is shown in FIGS. 1 and 2, where the typewriter in general is indicated by the reference number 21, having keys 22, a space bar 22 a space bar link 22", a carriage 23, a plastic casing 24 a ribbon 25, ribbon reels 26, reel Shields 27, a reversing lever 28, a reversing link 29 between the ribbon reels.

26 and a universal bar 30, activated by all of the keys of the typewriter to rotate with a drive shaft 31. Type bars 15 are operated through links 16 and key levers by the keys 22. The key levers 17 also operate universal bar 30. r

Shown in FIG. 2 in a cross-sectionalview is a base 32 of the typewriter, the reversing lever28 by which the direction of travel of a ribbon can be reversed, the drive shaft 31 and the universal bar 30.

Referring now to FIG. 3, encased. ribbon reel assemblies can be seen at 33, and ends of cams 34A and 348 which control the direction of travel can be seen protruding from slots in the ribbon reel assemblies.-

Arms 35 near the ends of. the drive shaft 31, are shown entering slots 37 to drive support plates 38 (FIG. 4,); can be seen in FIG. 4, the support plates 38carry pawls 39A and 39B in the left hand ribbon reel assembly and 39C and 39D in the right hand ribbon reel assembly. The pawls 39 A, B, C and D are biased by means of pawl springs 40 which press against pawl spring stops 41, the pawl springs being integrally molded with the pawls, all being mounted on support plates 38. The support plates 38 are biased toward a rest position as shown in FIG. 4 by means of biasing fingers 42 which are integrally molded with the support plates. The biasing fingers 42 press against a casing 43 when the support plate 38 is displaced from rest position; the casing 43 is mounted in a frame member 44.

In the cam positions as shown in FIG. 4, the cam 34A permits the pawls 39A and 398 to engage a ratchet wheel 45. The cam 34B holds the pawls 39C and 39D away from the ratchet wheel 45 in the right hand reel assembly. As a result the right hand ratchet wheel 45 and a shaft 46 centered within it can rotate freely under the urging of the ribbon reel mounted above as the reel is drawn by the ribbon being pulled toward the left hand reel assembly.

Rotation of the drive shaft 31 as shown in FIGS. 5 and 6 causes the arm in the slot 37 to displace the support plates 38 in the direction shown by the straight, vertical arrow (FIG. 5). This motion engages the pawl 39B with the ratchet to rotate it in the direction shown by the curved arrow. When the typewriter key causing this action is released, the drive shaft 31 rotates back to its rest position carrying the arm 35 with it and the pawl 39A engages the ratchet 45 to complete the rotation of the ratchet wheel through a distance corresponding to one pitch. It should be noted that pawls 39C and 39D are placed in the opposite sense with respect to the right hand ratchet wheel 45 and the ratchet wheel teeth similarly are oriented in the opposite direction to those of the wheel of the left hand assembly so that when the cam 348 permits the pawls in the right hand assembly to engage the ratchet wheel, the direction of rotation is opposite to that when the left hand ratchet wheel is driven.

As best seen in FIG. 6, the support plates 38 have a slotted opening 46 for passage of the shaft 46 therethrough and for permitting motion of the support plate 38.

The spacial relationships of the components of the ribbon reel assembly are shown in the exploded perspective view, FIG. 7. This view shows the reversing lever 28 joined to the cam 34A and makes clear how the pawls 39A and 39B are pivoted on the support plate 38. Also shown is the ribbon reel support 47.

A compact escapement cartridge 50 which controls the movements of the carriage is shown in FIG. 8. A slide bar 51 moves in a slide bar slot 52 in a rearward direction under the urging of an arm 53 which is rotated in a clockwise direction (as viewed in FIG. 2) both by the typewriter keys 22 and by the space bar 22. The arm 53 is rotated by depression of the space bar 22 and leftward movement of the space bar link 22". The action of the keys 22 in rotating the arm 53 will be explained below. The arm 53 enters the slide bar 51 in a recess 54. The rearward motion of the slide bar 51 actuates an escapement, indicated generally by the numeral 55.

The escapement 55 consists of pawls 56 and 57 joined respectively to integrally molded biasing fingers 58 and 59. Slide bar 51 is connected to pawl 56 through a pin 60 molded into the slide bar 51 and a recess 61 in the pawl 56 which receives the pin 60. A ratchet wheel 62 is the remaining component of the escapement. The wheel 62 carries for conjoint rotation a gear 63 which is the pinion to a rack gear 64. The action of the escapement will be described below.

The escapement can be disconnected from the carriage by rearward motion of a carriage release link 65 which draws a pawl displacement bar 66 in arearward direction and rotates a bell crank 67 to which it is connected through a pin 68 in a clockwise direction. The bell crank pin 67 is thereby caused to draw the pawl 57 away from the escapement wheel 62. The pawl 56 remains disengaged from the wheel, the carriage therefore being freed for motion to either side.

The force to drive the carriage is supplied by a spring pulley consisting of a housing 71 and a clockspring 74. The housing 71 is integrally molded with an escapement drive pinion gear 73 which powers the carriage through the rack gear 64. The gear 73 engages the rack gear 64 through an opening 73 in the cartridge 50. The inner end of the spiral clockspring 74 is mounted fixedly in a cylinder 75 at its center.

A bottom view of the escapement drive is shown in FIG. 10 where 76 generally indicates a tensioning device for the clockspring 74. The cylinder 75 (FIGS. 8 and 9) protrudes through an opening in the lower face of the cartridge 50 where it is fixedly joined to a ratchet wheel 77 associated with a pawl 78 which is biased toward the ratchet wheel 77. The cylinder 75 can be rotated by means of the wheel 77-to increase the tension in the clockspring without counteraction by the pawl 78. If it is desired to decrease the tension of the spring, the pawl can be separated from the ratchet wheel manually since thetension-adjustment assembly is outside the cartridge 50.

The spring pulley consisting of the housing 71 and spring 74 is mounted within a cylindrical, elevated portion 72 of the cartridge 50 (FIGS. 8 and 9). The ratchet wheel 77 is preferably integrally molded with the cylinder. The pawl 78 is pivoted on an integrally molded shaft 78' within the cartridge 50 (FIG. 1 1), and passes through the slot 78" to engage the ratchet wheel 77.

Further views of the escapement mechanism are given in FIGS. 12 and 13. Turning first to FIG. 12, the slide bar 51 is shown in rearward movement under the urging of the arm 53. Pawls 56 and 57 are thereby rotated in counterclockwise direction. The rotation of pawl 57 is brought about by engagement of a boss 79 with the rearward wall of a recess 80 of the upper pawl 57 as shown in FIG. 13. At this stage the lower pawl 56 releases the escapement wheel 62 in a counterclockwise direction through a distance corresponding approximately to half the pitch distance.

When the operative typewriter key is released, the pawls 56 and 57 rotate in a clockwise direction under the urging of the biasing fingers 58 and 59. In this rotation the pin 60 in the recess 61 is displaced in a frontward direction carrying with it the slide bar 51.

The method by which the release of the carriage is effected has already been explained, in connection with FIG. 8. FIG. 13 shows why the limited movement of the pawl 57 by the pin 69 does not affect the position of the pawl 56. This is due to the recess 80 which receives the boss 79 with sufficient backlash clearance.

The method of freeing the carriage forremoval from the typewriter can be seen in FIG. 8 where 81 is a carriage latch movable in a rearward direction. A latch boss 82, which normally provides a terminal stop for the carriage, is moved out of the way by this rearward displacement and permits complete removal of the carriage from the typewriter. Return of the latch to the rest position is provided by biasing fingers 83, integrally molded with the latch 81.

The manner in which bearings 84 for the ribbon vibrator are mounted on the cartridge 50 is shown in FIGS. 14 and 15. A ribbon vibrator'shaft 85 passes through the bearings 84. A ribbon holder 86 is shown in FIG. 14. Depression of a typewriter key moves a key link 88 in a leftward direction pulling a key slide bar 89 in the same direction. The upper portion of the key slide bar 89 is bifurcated into arms 90 within notches 91 in the cartridge 50. Lower arms 92 and upper arms 93 of the ribbon support within the notches 91 are thereby moved in clockwise rotation, moving the ribbon holder 86 and the ribbon 25 into printing position.

At the same time, the finger 88' on the key link 88 engages and rotates the arm 53 thereby actuating the escapement.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the. above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. g

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. In a typewriter, a unitary escapement cartridge control for a carriage to which is affixed a rack gear, comprising a molded encasement having an access slot and openings therein, a slide bar slidable in said slot, said slide bar being actuatable through a displacement and return cycle by depression and release of a typewriter key or of a space-bar, an escapement mechanism including two pawls, each having an integrally molded biasing finger and a ratchet wheel in I said encasement operatively connected to said slide bar through said pawls and rotatable through the pitch distance of said ratchet wheel by one cycle of said slide bar,v said escapement mechanism engaging said rack gear through a first opening, and biasing means within said encasement for urging said carriage in a single direction, said biasing means engaging said rack gear through a second opening in said cartridge encasement, thereby providing for intermittent displacement of said carriage in response to actuation of a typewriter key or space bar.

2. A unitary escapement cartridge control as defined in claim 1, wherein the first of said pawls is so biased that in rest position it engages said ratchet wheel, holding it against rotation, and further comprises a second slot in said encasement adjacent said first pawl, a second slide-bar in said second slot, said second slide bar being rearwardiy slidable in said second slot by an externally applied force, and retracting means, opera tively connecting said second slide bar with said first pawl for disengaging said first pawl from said ratchet wheel, thereby releasing said ratchet wheel for unrestricted rotation and freeing said carriage from constraint against movement to either side.

3. A unitary escapement cartridge control as defined in claim 1, wherein said biasing means comprises a cylindrical housing within said encasement, a gear mounted coaxially with said housing at one end of said housing for conjoint rotation therewith, part of said gear protruding through the second of said openings in said encasement and engaging with said rack gear on said carriage, a cylinder centered in said housing, one end of said cylinder protruding through said second opening in said encasement, said cylinder being rotatable by an externally applied force to a fixable position, and a clockspring within said cylindrical housing operatively connecting said housing; with its coaxially mounted gear and said cylinder so that movement of said carriage by an externally applied force in a direction opposite to said single direction tensions said clockspring, and so that said clockspring drives said rack gear and carriage in said single direction in conformity with the action of said escapement in response to actuation by keys and space bar.

4. A unitary escapement cartridge control as defined I in claim 3, wherein the position of said cylinder subsequent to rotation is fixed by means of a position-fixing ratchet mounted on said cylinder and a third pawl,

said position-fixing ratchet rotating conjointly with said cylinder in a direction such that the tension in said clockspring is increased. l

5. A unitary escapement cartridge control as defined in-claim 4, wherein said position-fixing ratchet and said third pawl are mounted externally of said encasement,

thereby making it possible to disengage said third pawl from said position-fixing ratchet manually and rotate said cylinder to a position of lower tension and to fix said cylinder in such position by re-engagement of said third pawl with said position-fixing ratchet.

6. A unitary escapement cartridge control as defined in claim 1, wherein a third slide bar is disposed slidably in a third slot in said encasement, said third slide bar in rest position blocking removal of said carriage from said typewriter, said third slide bar being movablerearwardly by an externally applied force to permit removal of said carriage, said third slide bar having integrally molded fingers which are stressed in rearward motion of said slide bar, said fingers urging said third slide bar to rest position after removal of said externally applied,

force.

7. A unitary escapement cartridge control as defined in claim 1, wherein said encasement cartridge has opposing faces, and a notch on each side of said first slot further comprising a pair of bearings mounted on one of said faces in the region of said first slot, a vibrator shaft mounted rotatably in said bearings, two vibrator bell cranks coupled to each other for conjoint rotation and mounted on said vibrator shaft as a fulcrum, with a first leg of each vibrator bell crank movable within one of said notches in response to activation by a key, and a ribbon holder mounted on the second legs of said vibrator bell cranks, said ribbon holder being vibratab le between a lower rest position and an upper position for registering of a character as the result of activation of said vibrator bell cranks by a key.

8. In a typewriter, a unitary escapement cartridge control for a carriage to which is affixed a rack gear, comprising a molded encasement having an access slot and openings therein, a slide bar slidable in said slot, said slide bar being actuatable through a displacement and return cycle by depression and release of a typewriter key or of a space-bar, an escapement l mechanism including two spring biased pawls, a ratchet wheel in said encasement operatively connected to said 

1. In a typewriter, a unitary escapement cartridge control for a carriage to which is affixed a rack gear, comprising a molded encasement having an access slot and openings therein, a slide bar slidable in said slot, said slide bar being actuatable through a displacement and return cycle by depression and release of a typewriter key or of a space-bar, an escapement mechanism including two pawls, each having an integrally molded biasing finger and a ratchet wheel in said encasement operatively connected to said slide bar through said pawls and rotatable through the pitch distance of said ratchet wheel by one cycle of said slide bar, said escapement mechanism engaging said rack gear through a first opening, and biasing means within said encasement for urging said carriage in a single direction, said biasing means engaging said rack gear through a second opening in said cartridge encasement, thereby providing for intermittent displacement of said carriage in response to actuation of a typewriter key or space bar.
 2. A unitary escapement cartridge control as defined in claim 1, wherein the first of said pawls is so biased that in rest position it engages said ratchet wheel, holding it against rotation, and further comprises a second slot in said encasement adjacent said first pawl, a second slide-bar in said second slot, said second slide bar being rearwardly slidable in said second slot by an externally applied force, and retracting means operatively connecting said second slide bar with said first pawl for disengaging said first pawl from said ratchet wheel, thereby releasing said ratchet wheel for unrestricted rotation and freeing said carriage from constraint against movement to either side.
 3. A unitary escapement cartridge control as defined in claim 1, wherein said biasing means comprises a cylindrical housing within said encasement, a gear mounted coaxially with said housing at one end of said housing for conjoint rotation therewith, part of said gear protruding through the second of said openings in said encasement and engaging with said rack gear on said carriage, a cylinder centered in said housing, one end of said cylinder protruding through said second opening in said encasement, said cylinder being rotatable by an externally applied force to a fixable position, and a clockspring within said cylindrical housing operatively connecting said housing with its coaxially mounted gear and said cylinder so that movement of said carriage by an externally applied force in a direction opposite to said single direction tensions said clockspring, and so that said clockspring drives said rack gear and carriage in said single direction in conformity with the action of said escapement in response to actuation by keys and space bar.
 4. A unitary escapement cartridge control as defined in claim 3, wherein the position of said cylinder subsequent to rotation is fixed by means of a position-fixing ratchet mounted on said cylinder and a third pawl, said position-fixing ratchet rotating conjointly with said cylinder in a direction such that the tension in said clockspring is increased.
 5. A unitary escapement cartridge control as defined in claim 4, wherein said position-fixing ratchet and said third pawl are mounted externally of said encasement, thereby making it possible to disengage said third pawl from said position-fixing ratchet manually and rotate said cylinder to a position of lower tension and to fix said cylinder in such position by re-engagement of said third pawl with said position-fixing ratchet.
 6. A unitary escapement cartridge control as defined in claim 1, wherein a third slide bar is disposed slidably in a third slot in said encasement, said third slide bar in rest position blocking removal of said carriage from said typewriter, said third slide bar being movable rearwardly by an externally applied force to permit remOval of said carriage, said third slide bar having integrally molded fingers which are stressed in rearward motion of said slide bar, said fingers urging said third slide bar to rest position after removal of said externally applied force.
 7. A unitary escapement cartridge control as defined in claim 1, wherein said encasement cartridge has opposing faces, and a notch on each side of said first slot further comprising a pair of bearings mounted on one of said faces in the region of said first slot, a vibrator shaft mounted rotatably in said bearings, two vibrator bell cranks coupled to each other for conjoint rotation and mounted on said vibrator shaft as a fulcrum, with a first leg of each vibrator bell crank movable within one of said notches in response to activation by a key, and a ribbon holder mounted on the second legs of said vibrator bell cranks, said ribbon holder being vibratable between a lower rest position and an upper position for registering of a character as the result of activation of said vibrator bell cranks by a key.
 8. In a typewriter, a unitary escapement cartridge control for a carriage to which is affixed a rack gear, comprising a molded encasement having an access slot and openings therein, a slide bar slidable in said slot, said slide bar being actuatable through a displacement and return cycle by depression and release of a typewriter key or of a space-bar, an escapement mechanism including two spring biased pawls, a ratchet wheel in said encasement operatively connected to said slide bar through said pawls and rotatable through the pitch distance of said ratchet wheel by one cycle of said slide bar, said escapement mechanism engaging said rack gear through a first opening, and biasing means within said encasement for urging said carriage in a single direction, said biasing means engaging said rack gear through a second opening in said cartridge encasement, thereby providing for intermittent displacement of said carriage in response to actuation of a typewriter key or space bar. 